Temperature regulator



June 24, 1947.

1.; M. PUsTER TEMPERATURE REGULATOR 3 Sheets-Sheet 1 Original Filed001L521. 1942 v I zxnmslcm mm June 24,1947. I L. MLPUSTER 2,422,924

TEMPERATURE REGULATOR Original Filed Oct. 21. 1942 s Sheets-Sheet. 2

EXFANSIDN TANK BY PASS .kmmrpn. r

June 24,1947, j 1 L M pusTE-R v 2,422,924 TEIPERKTURE REGULATOR priginalFiled Oct. 21. 1942 3 Sheets-Sheet if Patented June 1947 UNlTED STATESPATENTLOFFICE 2,422,924 V TEMPERATURE nnoumroa Louis M; Poster,Knoxville, Tenm, assignmto The Fulton Sylphon Company, Knoxville, Tenn acorporation, of Delaware Original application October 21, 1942, SerialNo.

462,845. Divided and this 7, 1944, Serial No. 548,464

6 Claims. (Cl. 236-34) application August signed operation of theregulator, causing, for example, in some structures heretofore proposed,

the by-pass valve member to float out of contact with its seat andpermit a continuous flow of the cooling medium through the bypass eventhough that temperature has been attained wherein only A circulationthrough the radiator is desired.

degree. While applicable to cooling systems for surface vehicles andinstallations, as will be hereinafter apparent, the present invention isof partlcular utility when applied to the coolingsystems of liquidcooled airplane engines.

Cooling systems of the type employing a bypass through which circulationis maintained durlng the warming up period of the engine, and

before the cooling medium reaches a predeter-' mined degree, have therecognized advantage that much time may be saved in bringing the engineto that temperature at which it is designed to operate efllcie'ntly.Systems of this character of necessity entail valve control of theby-pass and of the main circulation through the radiator,

involving the use of a thermostat which, in order to provide for therequisite amount of valve movement, is ordinarily of the type employingan expansible and collapsible chamber responsive to variations inpressure generated therein by a, volatile liquid. Such expansible andcollapsible chambers being pressure responsive elements also respond tofluctuations of pressure exteriorly thereof. Thus a designed operationat ground level ceases to hold true when a plane has reached highaltitudes because the decrease in atmospheric pressure acting on thecooling medium decreases the external pressure on the pressureresponsive vessel, whereby the latter can respond to a lower interiorpressure. As a plane will operate at a wide variety of altitudes eachhaving its own atmospheric pressure, the variations in pressure on theliquid in the cooling system are accordingly productive of a constantlyvarying back pressure on the thermostat with a consequent variation inthe temperature response thereof. Furthermore, the thermostat is alsoresponsive to variations of pressure in the cooling liquid itselfarising from varying conditions of operation of the pump, valves, etc.Hence the combined eitect of the varying pressures on the thermostat mayseriously interfere with the de- In my parent application Serial No.462,845, filed October 21, 1942, of which the present application is adivision, there has been disclosed and claimed a temperature regulatorof the character referred to wherein the operation of the valvemechanism is independent of fluctuations of pressure in the coolingliquid whether caused by variations of atmospheric pressure due toaltitude or by variations in the pressure in the liquid caused by theoperation of the cooling system itself.

It is an object of the present invention to provide a temperatureregulator for a cooling system of an internal combustion engine of thetype employing aby-pass which has improved safety mechanism to obtainmaximum flow of the cooling medium through the system when a danger-,ous temperature has been reached, and which while particularly adaptedfor use in a regulator as above characterized is also of general utilityin introducing, a safety feature 'into temperature regulators of theby-pass type.

Another object of this invention is to provide a. device of the typecharacterized which is relatively simple and compact in structure, andwhich can be manufactured and installed at relatively low cost, andwhich at the same time is highly eflicient in service.

- Other objects ofthe invention will appear as the description of theinvention proceeds.

This invention is capable of receiving a variety of mechanicalexpressions, three of which have been illustrated on the accompanyingdrawings, but it is to be expressly understood that the drawings are forpurposes of illustration only and are not to be construed as definitionsof the limit of the invention, reference being had to the appendedclaims for that purpose. 2

Referring in detail to the drawings, wherein the same referencecharacters are employed to designate corresponding parts in the severalfigures,

Fig. 1 is a schematic view of a, cooling system of an internalcombustion engine embodyin the invention;

Fig. 2 is an enlarged and more detailed view of the regulatorillustrated generally in the embodiment of Fig. 1;

Fig. 3 is another schematic view of a cooling system of an internalcombustion engine embodying the invention;

Fig. 4 is an enlarged and more detailed view of the regulatorillustrated generally in the embodiment of Fig. 3; and

Fig. 5 illustrates yet another embodiment of the invention.

Referring first to Fig. 1, there is diagrammatically illustrated acooling system for an internal combustion engine In which includes upperwater line H and lower water line l2 in communication with any suitableradiator l3. Interposed between the upper waterline l I and the bottomwater line i2 is a by-pass l4, and at the junction of said by-pass withthe bottom water line as here shown is installed in any suitable way aregula-' tor l5 embodying the present invention, this particularembodiment therefore being particularly adapted for installation in abottom water line.

Referring now to the more detailed illustration of the embodiment of theregulator of Fig. 1 to be found in Fig. 2, the regulator as hereillustrated includes a housing which may be composed of any suitablenumber of parts, shown as composed of a cup-shaped section i6 having aninlet 11 for suitable attachment to and in communication with theby-pass 14, a central section i8 to be referred to in more detail, and alower cup-shaped section IQ for the compensating element to bedescribed. Said sections [8, i8 and I9 may be united in any suitableway, as by appropriate bolts or screws 20, with suitable packing 2|, ifdesired, to prevent leakag at the joints between the sections of thehousing.

Section l8 of said housing is provided with a pair of nipples 22 and 23,here shown as at opposite sides of the section and substantially inalignment, although such arrangement is in no respect essential. Nipple22 is designed. to be suitably attached to and communicate with thebottom water line l2, while nipple 23 is designed to be suitablyattached to and communicate with the radiator l3, as by a short sectionof conduit designated 24 in Fig. 1, but obviously nipple 23 may be madeof appropriate length for direct attachment to the outlet of theradiator. Interiorly, section i8 has a partition wall 25 apertured at 26and 21 to provide a pair of aligned valve ports with which co-operatethe main valve members to be described. Section I8 is also suitablypro.- vided with a by-pass port 28, here shown as formed in the wall 29of section l8 on that side of said section to which the housing sectionI8 is attached.

Mounted in any suitable way in said housing section I6 is a thermostatof any suitable size and construction, here shown as in the form of anexpansible and collapsible chamber defined by a corrugated tubular metalwall or bellows 30 provided with a stationary end wall 3| which isfixedly attached in position in the housing, as by a threaded boss 32extending through an aperture 33 in a bridge 34 formed integrally withor attached to the housing section l8 and locked in position as by a nut35. Th opposite and movable end wall 38 closing the opposite end of thechamber 31 of said thermostat, and which chamber is charged with anysuitable thermo-sensitive fluid, preferably a volatile liquid partiallyillustrated as threadedly secured to a stud 39 projecting from the endwall 36. Slidingly mounted on said stem 38 but normally locked againstrelative movement with respect thereto as hereinafter explained is asleeve 40 having its inner end beveled so as to provide a cam surface4!. Fixedly attached to the sleeve 40 in any suitable way, as by screwthreads at 42, is a sleeve 43 which at its opposite end is also slidablymounted on said stem 38, and to said sleeve 43 is attachedin anysuitable way, or as shown made integral therewith, the valve members 44and 45 for co-operation with the valve ports 28 and 21, respectively,heretofore referred to. As illustrated, valve member 44 has .a slidinfit in its port 26, while valve member 45 has seating engagement withthe periphery of the port 21, but as will be apparent any other suitableform of poppet valve structure may be employed.

Also mounted on the sleeve 40, as by the threaded connection at 46, isaby-pass valve 41, said valve having a diameter such that its effectivearea when closed is equal to the effective area of the movable end wall36 of the thermostat chamber 31, to the end that said chamber and saidvalve member 41 will have the same response to fluid pressure whetherthe by-pass valve is open or closed as hereinafter explained. Valvemember 41 may be of any suitable construction, bein shown as somewhatdished so as to make a line contact with the periphery of the port 28,but any other suitable construction of seating valve may be used.Interposed between said valve member 41 and the end wall 36 of chamber31, here shown as formed reentrantly so as to co-operate with thetubular stop element 48 to limit the collapse of the bellows 30, is acoil spring 49 for a purpose to be explained.

-As before noted, stem 38 is hollow for a portion of its length toprovide an interior bore 50. The inner end of said bore as shown isprovided with a recess 5| above which is a seat 52 to receive a block 53of suitable metal that will melt or at least become sufiiciently soft tofunction as hereinafter explained if and when the temperature of thecooling medium reaches a predetermined degree that is considereddangerous. Slidably mounted in the bore is a plunger which has a head 54slidably engaged with the wall of said bore. Projecting from said head54 is an extension 55, and outwardly from said head 54 said plunger iscut away as shown at 56. Mounted within the bore 50 between the end ofthe plunger and the stud 39 is a coil spring 51 which holds theextension 55 of the plunger in contact with the meltable block 53 and.when said block melts or sufliciently softens, forces the extension 55toward or into the recess 5| so as to bring the cutaway portion 58 intothe position previously occupied by the head 54. Mounted in an aperturein the wall of the stem 38 is a ball or other suitable trigger member58, said ball being freely movable in said aperture but being normallyheld by the head 54 in a position in which it projects outwardly fromthe wall of the stem 38 inengagement with the cam surface 4| on the.inner end of the sleeve 48, which relationship is maintained by thetension of the spring 49 applied to the valve member 4'1 and hence tosaid sleeve 40 to which said valve 41 is attached.

, a -Upon melting or jsoitening or the block. ll sumciently to permitspring 51 to move the head I4 on the plunger from the position shown inthe drawings to one in which the cutaway portion 58 is brought oppositesaid ball II, ball I! is cammed into the cutaway portion 56 by the camsurface 4| ol' the sleeve 40 under the pressure applied to the latter bythe spring 49, whereupon the stem 38 is disconnected from the sleeve 40and the sleeve 43 with its valve members 44 and 45 carried thereby.Thereby the stem 38 becomes independent of the valve members 44 and 45,and as the sleeves -4l and 43 are now free to slide on the stem 38 theywill be moved by spring 49 to the position wherein valve member 41engages its seat to close the port 28, while valve members 44 and 45 aremoved to open to their maximum extent.

Mounted within the housing section It, as

ports 26 and 21 'hereinbefore referred to, is a pressure'compensatingelement in the form of an expansible and collapsible corrugated tubularmetal wall or bellows having a stationary end wall it suitably attachedto the housing wall, as by a stud 62 pro- 'jecting through an aperturein the housing wall with air or a suitable inert gas. a

When valve member 41 is open so that the twomovable end walls I6 and 64are subjected to the fluid pressure'in the housing the iluid pressureacts equally and oppositely on said two movable end walls connected bythe stem 38, so, that any fluctuation of pressure, whether due tochanges in atmospheric pressure or due to changes .in liquid pressurebecause ot the operation of the cooling system, is balanced out sincethe same fluctuation of pressure ar applied equally and in oppositedirections on the movable end wall 38 of the thermostat and on themovable end' wall 64 of the compensating chamber 65. When in the courseof operation the valve member 41 is engaged with its seat, preventing orsubstantially preventing circulation of the cooling medium through theby-pass, the fluctuations in pressure in the medium flowing through thehousing are applied to the movable end wall 64 of compensating chamber65 and the underside of the valve member 41, but as the eflective areasof the two movable end walls have been equated with that oi! the valvemember 41, the same compensating eifect'is still retained. Hence in noposition of the valve members will fluctuations of pressure in thecooling medium produce an undesired movement of saidvalve membersbecause saidvalve members now respond only to the variations of pressurecorresponding to temperature variations at the thermostat 31.

As will now beapparent, when the engine is first started the coolingmedium is relatively cold 'termined degree thermostat 31 begin toexpand,

decreasing the flow of cooling medium through the port 28, and thereforethrough the by-pass, while initiating and progressively increasing theflow or cooling medium through ports 26 and 21 and thereby through theradiator.v Progressive increase of temperature results in progressivemovements of the valve members until the bypassport 28 is closed and themain valve ports 28 and 21 are wide open, while a decrease intemperature results in a reverse movement of the parts to decrease theflow through the radiator and increase 'flow through the by-pass.Thereby the temperature of the cooling medium may be kept closely to thepredetermined intended temperature.

In the event that the temperature rises dangerously to that degree atwhich the block 53may melt or soften sufilciently to permit spring 51 tomove the plunger 54, 55 downwardly as viewed in the drawings, ball 59 iscammed into the cutaway portion 56 under the action of the spring 49 andthe valve members 44, 45 and 41 are thereby made independent of the stem38. Under these conditions spring 49 is free to expand to its full limituntil by-pass valve 41 closes the by-pass ever, if preferred, a leakageport may be provided in or around the valve member 41 so as to assure aslight circulation at all times through the chamber containing thethermostat and thereby render said thermostatmore quickly responsive tochanges of temperature in the cooling medium without introducin suchcirculation through the by-pass when the by-pass valve is closed aswould upset the intended operation of the regulator.

and the thermostat 31 is contracted to the posi- 1 tion shown whereinthe main valve members 44 and 45 close the ports 26 and 21 in the mainline of circulation through the radiator, while valve Fig. 3 illustratesanother embodiment of the present invention applied to what corresponds.

with the upper water line of a cooling system.

As here shown, engine 10 has a cooling water system including conduit 1!leading from the outlet of the engine jacket to the radiator 12, thecooling medium being returned to said jacket through water lin 13. Aby-pas 14 is interposed between water, lines 1| and 13 and the reg-'ulator of the present invention, here designated 15, is interposed atthe junction of the 'water line 1| with the by-pass 14. Thus thisembodiment is one suitable for installation in an upper water line.

Now referring to Fig. 4 for a detailed illustration of the embodiment ofthe invention diagrammatically indicated in Fig. 3, again the housing isshown as composed of three sections 16, 11 and 18 connected in anysuitable way, as by bolts or screws 19 with orwithout interposed packingas illustrated at 80. In this embodiment the inlet 8|, formed a a nippleon housing section 16, has suitable connection to and communication withthe conduit 1| leadin from the outlet of the water jacket, and outlet 82for connection to and communication with the conduit 1| leading to theradiator is formed as a nipple on housing section 18. A nipple 83 on thehousing section 11 is adapted to.be suitably connected to andcommunicate with the by-pass I4. As in the embodiment of Fig. 2, thethermostat is illustrated as formed by an expansible and collapsiblecorrugated tubular metal wall or bellows 84 having a stationary en wall85 suitably attached to the housing wall and a movable end wall 86, thechamber 81 thereby formed being suitably charged with a thermosensitivefluid, preferably a vaporizable liquid, as before explained. Fixed tosaid movable end wall 88 is a stud 88 to which is aflixed the valve stem89. At its opposite end valve stem 89 .is aflixed to a threaded stud 98projecting from the movable end wall 9I of. a pressure compensatingvessel 92 having its peripheral wall formed by an expansible andcollapsible tubular metal wall or bellows 93. The stationary end wall 94of vessel 92 is fixedly mounted in position, as by means of a bridge 95formed in or suitably attached to the wall of housing section I8, andsaid vessel 92 is charged as before explained. In the form here shownexpansive and contractive movements of the vessel 92 are guided by a pin96 fixed to one of the end walls of the vessel 92 and having itsopposite end slidingly related with a recess suitably provided thereat.Thermostat 81 and compensating vessel 92 may be formed, mountedandcharged as heretofore explained in greater detail in conjunction withthe embodiment of Fig. 2.

Slidingly mounted on the stem 89 is a sleeve 91 to which are affixed orsuitably formed integral therewith the valve members 98, 99 and I88,valve members 98 and I88 being shown as threadedly secured to the sleeve91 while valve mem-' ber 99 is shown as formed integrally with saidsleeve. As in the embodiment of Fig. 2, housing section II is providedwith an interior partition I8I provided with aligned apertures I82 andI83 to provide valve ports. In this embodiment removable threaded valveseat members are shown in said ports, but the ports could be formed,

by apertures in the partition as in the embodiment of Fig. 2,analogously as the embodiment of Fig, 2 could be provided with removablevalve seat members if desired. The housing section 1! is also providedwith a second partition I84 apertured to provide a valve port I85, herealso shown as provided with a removable valve seat member. as adapted tomake seating contact with the peripheries of the ports I82 and I85,respectively, but valve member 99 is of such size that it slides in theport I83, being illustrated as having wings I86 to guide the movementsof said valve member with respect to port I83.

The effective area of the valve member I88 when closed is equated withthe effective area of the movable end wall of chamber 92 in theconstruction shown in Figs. 3 and 4, so that even when valve member I88is closed the downward pressure on valve member I88, as viewed in thedrawings, is the same as that existing on the movable end wall 9| whenvalve member I88 is open. As in the embodiment of Fig. 2, the effectiveareas of the movable end walls of chambers 81 and 92 are equated andhence the balancing function heretofore explained is equally obtained inthis embodiment. In this embdiment the thermostat 81 is subjected to thetemperature of the cooling medium whether the main valve I88 is open orclosed, an therefore no leakage provision is required.

The embodiment of Fig. 4 shows an alternative Valve members 98 and I88are shown structure for introducing the safety feature described inconjunction with the embodiment of Fig. 2, operating on the sameprinciple but differing in detail. As here shown, the sleeve 91 isslidably mounted on stem 89 and fixedly attached, as by a threadedconnection, to a sleeve I8'I also slidably mounted on the valve stem 88.

.The inner end of sleeve I 81 is provided with a beveled surface I88 toprovide a. cam, and one or more balls I89 are mounted in apertures inthe wall of the bore of stem 89 normally locked in engagement with thecam surface I88 by a block of fusible metal II8. Surface I88 is held incontact with the ball or balls I89 by a coil spring III interposedbetween the valvemember 98 and the movable end wall 86 of thermostat 81.If the temperature rises sufliciently to melt-the block I I8, or softenit sufllciently, the balls are cammed inwardly into the melted orsoftened metal by the action of coil spring III transmitted to thesleeve I8'I through valve member 98 and to the cam surface I88 inengagement with said ballsl Thereby sleeve 91 is rendered free to slideon the valve stem 89 and, under the action of spring III, the valvemembers 98 and 99 are moved to close the by-pass ports and valve I88 ismoved to its wide open position.

The embodiment of Fig. 5 illustrates the present invention incorporatedin a structure having the compensating feature and the safety featureheretofore referred to but using only a single main valve and a singleby-pass valve which by reason of the relationship of their effectiveareas to the length of their strokes will produce a substantiallyconstant volume of liquid flow.

In the form shown in Fig. 5, the regulator again includes a housingwhich may be composed of any suitable number of parts but is shown ashaving a central section I 38provided in any suitable way with a nippleI3I for connection to the by-pasa, an end section I32 provided in anysuitable way with a nipple I33 for connection to the waterline andconstituting the inlet to the housing, and an end section I34 providedin any suitable way with a nipple I35 for connection to the water lineand providing an outlet for the housing. Said housing sections may beconnected in any suitable way, as by a plurality of bolts or screws I88,and suitable packing as shown at I3I may be interposed to preventleakage.

Mounted in any suitable way in the housing section I32 is a thermostatof any suitable size and construction, and here shown as in the form ofan expansible and collapsible chamber defined by a corrugated tubularmetal wall or bellows I38 provided with a stationary end wall I39 whichis fixedly attached in position in the housing, as by a threaded bossI48 extending through an aperture I ma bridge I42, formed integrallywith or attached to the housing section I32, and locked in position asby the nut I43. The opposite movable end wall I44 closing the oppositeend of the chamber I45 of said thermostat; and which chamber is chargedwith any suitable thermosensitive fluid, preferably a volatile liquidpartially filling said chamber as heretofore explained, has attachedthereto in any suitable way a stem I48.

' As here illustrated stem I46 carries a guide pin 'threadedly attachedat I52 to a boss or stem I53 projecting from the movable end wall I54 ofthe compensating vessel I55, whichls partially evacuated and chargedwith air or suitable inert gas, said movable end wall I54 havingsubstantially the same eflective area as the movable end wall Q40 ofsaid thermostat and said compensating vessel having the construction,function and manner of operation as heretofore explained in detail inconnection with the other embodiments. Said compensating vessel I55 hasa stationary end wall I55 mounted in any suitable way, as by a threadedboss I51 projecting through an aperture H55 in a bridge I55 attached toor formed integ with the housing section I34 and locked inpositionbyanut I50.

Slidably mounted on the stem 15I is a sleeve Ill which carries adjacentits opposite end, as by internal threads, a locking sleeve I52 having abeveled surface I53 at its inner extremity. The

wall of the hollowed portion of the stem I51 has efiective areas of themovable end walls of the thermostat I45 and the compensating vessel I55so that when the latter is shielded fromthe liquiol pressure by theposition of the valve member H55 the compensating action is stillobtained as above explained. Threadedly mounted at the inner end of thehousing section I32 is a valve seat member. I adapted to make linecontact with said surface I59. The opposite end of valvemember I68 isshown as beveled at "I to make seating contact with a beveled surfaceI12 on a seating member I13 suitably mounted, as by threads, in anaperture I14 in an internal partition I15 of the housing section I30.Partition N15 has a second and aligned aperture I15 in which is suitablymounted, as by threads, a guide member I11 for slidably receiving andguiding the tubular valve member I55.

interposed between the movable end wall I44 oi. the thermostat and asuitable seat provided on the valve member I55, here shown as providedin the arms I51, is a coil spring I18 reacting between the movable endwall on said thermostat and said tubular valve member so as to tend tourge the latter toward the right, as viewed in the drawings, saidtubular valve member with its sleeve I5I being normally locked againstmovement on the stem I5I by the interengagement between the balls I55,the plug I55 and the locking ring I52.

In operation, the cooling liquid enters the housing through the openingin'nipple I33, and

if said liquid is cold, as it will be normally at the beginning ofoperation, the thermostat I45 is contracted and valve member I55 is heldin contact with seat I10 whereby the liquid will flow through theinterior of said valve member I58 and out through the by-passopeningprovided by nipple K. As the liquid rises in temperature thethermostat I45 will expand moving the valve member I55 toward the rightas viewed in the drawing to permit flow through the port provided by theseat I10 while simultaneously advancing the beveled end "I of said valvemember I55 toward its seat I12 on the member I13. Continued rise of thetemperature will eventually cause the end I'1I of valve member I58 toengage its seat I12 on member I13, in which position flow thrcugh theby-pass is stopped and valve member I58 is in its most remote positionfrom its seat I 10, whereby all of'the liquid will flow through theoutlet to the radiator provided by the nipple I35.

If at any time the thermostat should become inoperative so that thetemperature of the liquid rises to a dangerous degree, such temperaturewill cause the plug I55 to soften or melt, whereby the balls I55 may becammed inwardly into the chamber in the hollowed portion of the stem I5Iby the action of the beveled extremity of ring I52 on said balls,whereby the sleeve I5I is free to slide on the stem I5I, and the coilspring I18 will thereupon move valve member I58 to its extreme openposition, causing the by-p ss to be completely closed and all of theliquid to flow through the outlet provided by the nipple I35.

The effective area of movable end wall I54 of compensating vessel I55 isequated as to effective area of the movable end wall I44 01' thethermostat I45, so that said compensating vessel will cooperate withsaid thermostat to balance out fluctuations in the pressure of theliquid either caused by variations of pressure due to altitude orvariations of pressure in the liquid itself, and when the compensatingvessel I55 is shielded by the valve member I58, the same action is isobtained because of the opposed pressures acting on the movable end wallI44 and the flanged end of valve member I55 having the same effectivearea.

Owing to the large efiective area of the valve ports and the relativelyshort stroke required to efiect maximum opening or closing, the volumeof flow of the liquid remains substantially constant whether valvemember I 58 is in engagement with its seat I10, or whether said valvemember is in engagement with its seat I12, or whether it is in anyintermediate position, as above explained.

It will therefore be perceived that by the present invention atemperature regulator has been provided wherein, upon the occurrence ofa dangerous condition resulting in a rise of temperature within thecooling system above that deemed safe or desirable, the thermostaticcontrol is disconnected from the valve mechanism and the latter is movedto its safety position, discontinuing the iiow or cooling medium throughthe by-pass and enforcing full through the radiator.

While the embodiments of the invention illustrated'on the drawings havebeen described with considerable particularity, it is to be ex-.

stricted thereto, as the same is capable of receiving a variety ofmechanical expressions, some of which will now readily suggestthemselves to those skilled in the art, while changes may be made in thedetails or the component elements, as in the matters of size,relationship, etc., and certain features used without other featureswithout departing from the spirit of this invention. While the inventionhas been illustrated as employed in a temperature regulatorincorporating compensation for variations in pressure which makes theregulator of particular utility in airplane engine service, it is to beexpressly understood that the invention is of wider utility, and is notto be restricted to use in such a regulator, because the safety featureclaimed herein circulation may be employed in any suitable coolingsystem of the by-pass type for stationary engines as well as engines forland, water or air vehicles whether with or without provision forcompensating changes in pressure in the cooling medium. The invention isalso applicable to temperature regulators for cooling systems employingother types or forms of thermostats, valve mechanism, etc.

Reference is therefore to be had to the appended claims for a definitionor this invention.

What is claimed is:

1. In a temperature regulator for the cooling system of an internalcombustion engine of the type employing a radiator and a by-pass aroundsaid radiator and a thermostatically operated regulator forpredetermining the flow of cooling medium through either or both of saidradiator and said by-pass including a thermostat subjected to thetemperature of the.cooling medium, a valve stem attached to saidthermostat, a sleeve surrounding. said stem and slidably mountedthereon, main and by-pass valve means mounted on said sleeve and formingwith said sleeve a unit adapted to he slid lengthwise of said stem,resilient means cooperating with said unit and urging the same in adirection to close the bypass valve, a detent interposed between saidstem and sleeve for normally locking said sleeve against slidablemovement on said stem, and means responsive to a dangerous rise in thetemperature of the cooling medium for normally holding said detent insleeve-locking position but operable upon the occurrence of thedangerous temperature to release said detent and permit said resilientmeans to move said sleeve and associated valve means to a positionclosing said by-pass and opening wide said main valve.

2. In a temperature regulator for the cooling system of an internalcombustion engine of the type employing a radiator and a by-pass aroundsaid radiator and a thermostatically operated regulator forpredetermining the flow of cooling medium through either or both of saidradiator and said by-pass including a thermostat subjected to thetemperature of the cooling medium,

.a valve stem attached to said thermostat, a sleeve surrounding saidstem and slidably mounted thereon, main and by-passvalve means mountedon said sleeve and forming with said sleeve a unit adapted to be slidlengthwise '01 said stem. resilient means cooperating with saidunit andurging the same in a direction to close the 'bypass valve, adetentinterposed between said stem and sleeve for normally locking saidsleeve against slidable movement on said stem, and means responsive to adangerous rise in the temperature or the cooling medium for normallyholding said detent in sleeve-locking position but operable upontheoccurrence of the dangerous temperature ,to release said detent andpermit said resilient means to move said sleeve and associated valvemeans to a position closing said by-pass and opening wide said mainvalve, said last named means including fusible metal engaging saiddetent to hold the. same in its sleeve-locking position.

resilient means cooperating with said unit and urging the same in adirection to close the bypass valve, a detent interposed between saidstem and sleeve for normally locking said sleeve against slidablemovement on said stem, and means responsive to a dangerous rise in thetemperature of the cooling medium for normally holding said detent insleeve-locking position but operable up-.

on the occurrence of the dangerous temperature to release said detentand permit said resilient means to move said sleeve and associated valvemeans to a position closing said by-pass and openingwide said mainvalve, said detent including a member mounted in and projecting from achamber in said stem, and fusible metal interiorly 01 said stem engagingsaid detent member to hold the same in its sleeve-locking position.

4. In a temperature regulator for the cooling system of an internalcombustion engine of the type employing a radiator and a by-pass aroundsaid radiator and a thermostatically operated regulator forpredetermining the flow of cooling medium through either or both of saidradiator and said by-pass including a thermostat subjected tothetemperature of the cooling medium, a valve stem attached to saidthermostat, a sleeve surrounding said stem and slidably mounted thereon,main and by-pass valve means mounted on said sleeve and forming withsaid sleeve a unit adapted to he slid lengthwise of said stem, resilientmeans cooperating with said unit and urging the same in a direction toclose the bypass valve. a, detent interposed between said stem andsleeve for normally locking said sleeve against slidable movement onsaid stem, means responsive to a dangerous rise in the temperature 01'the cooling medium for normally holding said detent in sleeve-lockingposition but operable upon the occurrence of the dangerous temperatureto release said detent and permit said resilient means to move saidsleeve and associated valve meansto a position closing said by-pass andopening wide said main valve, said detent including a member mounted inand projecting from a chamber in said stem, a spring-actuated plungerfor locking said detent member in projecting position, and a fusibleplug for locking said plunger against movement but operable to free saidplunger under a predetermined rise of temperature for spring actuatedmovement thereof to a position releasing said detent member.

5. In a temperature regulator for the cooling I system of an internalcombustion engine of the medium through either or both of said radiatorI and said by-pass including a thermostat subjected to the temperatureof the cooling medium, a valve stem attached to said thermostat, asleeve type employing a radiator and a by-pass around said radiator anda thermostatically operated regulator for predetermining the flow ofcooling medium through either or both of said radiator and said by-passincluding a thermostat subjected to the temperature of the coolingmedium, a valve stem attached to said thermostat, a sleeve surroundingsaid stem and slidably mounted thereon, main and by-pass valve meansmounted on said sleeve and forming with said sleeve a unit adapted to beslid lengthwise of said stem, resilient means cooperating with said unitand urging the same in a direction to close the bypass yalve, a detentinterposed between said stem and sleeve for normally locking said sleeveagainst slidable movement on said stem, and means responsive to adangerous rise in the temperature of the cooling medium for normally,

holding said detent in sleeve-locking position but operable upon theoccurrence of the dangerous temperature to release said detent andpermit said resilient means to move said sleeve and associated valvemeans to a position closing said by-pass and opening wide said mainvalve, said detent including a member mounted in and projetting from achamber in said. stem and a fusible member for locking said detentmember in its projecting position, and said sleeve including a camsurface cooperating with said detent memher for camming the same intosaid chamber upon fusion of said fusible member.

6. In a temperature regulator for the cooling system of an internalcombustion engine 01' the type employing a radiator and a by-pass aroundsaid radiator and a thermostatically operated re ulator forpredetermining the flow of cooling medium through either or both of saidradiator and said by-pass including a thermostat subjected to thetemperature of the coolingmedium, a valve stem attached to saidthermostat, a sleeve surrounding said stem and slidably mounted.

thereon, main and by-pass valve means mounted on said sleeve and formingwith said sleeve a unit adapted to be slid lengthwise of said stem,resilient means cooperating with said unit and urging the same in adirection to close the bypass valve. a detent interposed between saidstem and sleeve for normally locking said sleeve against slidablemovement on said stem, means responsive to a dangerous rise in thetemperature the cooling medium for normally holding said 14 detent insleeve-locking position but operable upon the occurrence oi. thedangerous temperature to release said detent and permit said resilientmeans to move said sleeve and associated valve means to a positionclosing said by-pass and opening wide said main valve, said detentincluding a member mounted in andprojectins from a chamber in said stem,a fusible plug for locking said detent member in its projecting polosition, and cam means on said sleeve cooperating with said detent memberand operable under the action of said resilient means to cam said detentmember into said chamber and release said sleeve upon response of saidfusible plug to said dangerous temperature.

- LOUIS M. PUS'I'ER.

REFERENCES CITED The following references are or record in the file ofthis patent:

UNITED STATES PA'IENTS Number Name v Date 1,126,914 Sullivan Feb. 2,1915 1,243,998 Smyly Oct. 23, 1917 1,919,508 Grimth July 25, 19331,941,298 Green Dec. 26, 1933 1,952,516 Sperry Mar. 27, 1934 FOREIGNPATENTS 7 Number Country 1 Date 122,606 Austria Dec. 15, 1930

